The great majority of plants gain access to soil nutrients and enhance their performance under stressful conditions through symbiosis with arbuscular mycorrhizal fungi (AMF). The benefits that AMF confer vary among species and taxonomic groups. However, a comparative analysis of the different benefits among AMF has not yet been performed.We conducted a global meta-analysis of recent studies testing the benefits of individual AMF species and main taxonomic groups in terms of plant performance (growth and nutrition). Separately, we examined AMF benefits to plants facing biotic (pathogens, parasites, and herbivores) and abiotic (drought, salinity, and heavy metals) stress.AMF had stronger positive effects on phosphorus nutrition than on plant growth and nitrogen nutrition and the effects on the growth of plants facing biotic and abiotic stresses were similarly positive. While the AMF taxonomic groups showed positive effects on plant performance either with or without stress, Diversisporales were the most beneficial to plants without stress and Gigasporales to plants facing biotic stress.Our results provide a comprehensive analysis of the benefits of different AMF species and taxonomic groups on plant performance and useful insights for their management and use as bio-inoculants for agriculture and restoration.

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Information about the interaction between arbuscular mycorrhizal fungi (AMF) and the false root-knot nematode Nacobbus aberrans (Thorne, 1935) Thorne & Allen, 1944 is scarce. The effect of Glomus intraradices Schenk & Smith on tomato (Lycopersicon esculentum L.) cv. Platense inoculated with nematode juveniles from Lisandro Olmos (Argentina) was studied under greenhouse conditions. Six treatments with five replications were performed. After 80 days, nematode reproduction and percentage of AMF colonization in roots were estimated. Some plant growth parameters were also measured. In general, plants with AMF and AMF plus nematodes grew as well as the control without AMF and without nematodes. Furthermore, G. intraradices was beneficial in reducing nematode-induced damage in roots (lower number of galls) as well as in having a suppressive effect on parasite reproduction. This is the first study on the use of G. intraradices as a possible strategy in the control of N. aberrans in tomato.

Arbuscular mycorrhizal fungi (AMF) colonize land plants in every ecosystem, even extreme conditions such as saline soils. In the present work we report for the first time the mycorrhizal status and the vertical fungal distribution of AMF spores present in the rhizospheric soil samples of four species of Chenopodiaceae (Allenrolfea patagonica, Atriplex argentina, Heterostachys ritteriana and Suaeda divaricata) at five different depths in two saline of central Argentina. Roots showed medium, low or no colonization (0–50%). Nineteen morphologically distinctive AMF species were recovered. The number of AMF spores ranged between 3 and 1162 per 100 g dry soil, and AMF spore number decreased as depth increased at both sites. The highest spore number was recorded in the upper soil depth (0–10 cm) and in S. divaricata. Depending of the host plant, some AMF species sporulated mainly in the deep soil layers (Glomus magnicaule in Allenrolfea patagonica, Septoglomus aff. constrictum in Atriplex argentina), others mainly in the top layers (G. brohultti in Atriplex argentina and Septoglomus aff. constrictum in Allenrolfea patagonica). Although the low percentages of colonization or lack of it, our results show a moderate diversity of AMF associated to the species of Chenopodiaceae investigated in this study. The taxonomical diversity reveals that AMF are adapted to extreme environmental conditions from saline soils of central Argentina.

composition can influence ecosystemic processes either through affecting plant community composition and thus its processes rates, or soil microbial communities, which are directly involved in nutrient cycling (Rillig 2004). According to Pärtel et al. (2016), soil microorganisms are considered a potentially suitable target for studying regional and local effects on diversity. The symbiosis with AMF not only increases nutrient uptake by the plant of mainly phosphorus (P) and nitrogen (N) in exchange for plant-assimilated carbon (C), but also improves the tolerance of plants to various biotic and abiotic stresses such as pathogens, salinity, and drought (Smith and Read 2008). External factors (abiotic and biotic) and intrinsic properties of species (dispersal ability, rates of speciation and extinction) affect the AMF geographical distributions (Chaudhary et al. 2008). For instance, the abiotic factors of temperature and precipitation constrain AMF occurrence (Davison et al. 2015) while biotic ones such as host preferences determine the rhizospheric AMF community (Senés-Guerrero and Schüßler 2016; Soteras et al. 2016). Moreover, anthropogenic activities like agricultural practices that alter soil conditions could influence the occurrence of AM fungal taxa (Cofré et al. 2017). At the same time, either external or internal factors may indirectly influence each other, causing changes in AMF taxa occurrence and distribution (Chaudhary et al. 2008). Currently, an increasing number of studies attempt at unravelling the worldwide geographical patterns of AMF (

The aim of this study was to compare the arbuscular mycorrhizal fungal (AMF) community of the rhizosphere and inside the roots of the perennial Polylepis australis tree. Three forest types differing in their structural complexity due to anthropogenic disturbances were chosen at three different sites at the high mountains of central Argentina. Rhizosphere spores and P. australis roots of four randomly selected trees were isolated from 36 soil samples, DNA was extracted and the 18S rDNA fragments were amplified by nested-PCR. The products were analyzed by DGGE and the bands were excised for sequencing. In total, 36 OTUs were defined from 56 DGGE bands successfully sequenced. Forest disturbance types showed similar communities of AMF, as rhizosphere spores and within the roots of P. australis. However, DGGE clustering showed mainly differences between rhizosphere spores and root-colonizing AMF. Members of Glomeraceae, Pacisporaceae, Acaulosporaceae and Gigasporaceae were shown in rhizosphere spore samples. Root samples showed only members of Acaulosporaceae and Gigasporaceae, which might be complementary in terms of soil resources exploration. The prevalence of the root system with their community of symbionts might explain the resilience of AMF soil communities to forests structural changes. This study presents evidence of a possible preference in the AMF-P. australis interaction. 2015 Elsevier B.V. All rights reserved.

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Fleshy hypogeous fungi produce scents that enable mycophagous mammals and invertebrates to locate them and disperse their spores. The European wild boar (Sus scrofa) was introduced in central Argentina in 1900s and later expanded into Patagonia. Here, we determined the diversity and abundance of fungal taxa, and the frequency of hypogeous fungal spores in wild boar feces in Patagonia. We collected fecal samples on Isla Victoria, Nahuel Huapi National Park, and identified fungi using microscope and DNA metabarcoding of ITS2 rDNA. Hypogeous fungal spores occurred in almost all fecal samples. The most abundant species belonged to the genera Hysterangium, Melanogaster, Radiigera and Gautieria. In addition to the symbiotrophic hypogeous taxa, we also identified numerous pathotrophic and saprotrophic taxa. Not only diverse native hypogeous fungi, but also introduced ones are part of the diet of the wild boar in forests of Patagonia. If viable, introduced fungi are being dispersed as far as 2.5 km from the nearest plantation, highlighting how the introduced wild boar might alter the local distribution and composition of fungal communities.